Hi, I am having major issues with my car and need help please!!
it's a 92 240sx hatch with a 5 speed ka24de. The car was previously an automatic but my friend did a 5 speed swap a few years back. I am not good at and know nothing about wiring.

Ok so about two weeks ago I was driving to my dr. Appt. ( diagnosed with leukemia back in oct.) and my car felt like it wanted to die but before it did I was able to pull over to the curb but it was on a st. that said no stopping anytime ( lol right in front of my hospital). So I look under the hood and saw that my ENG CONT fuseable link blew. I had my mom come meet me and take me to get a new one but Nissan didn't have one and said it would take a day to get it. So I had her take me to autozone to see if there was a possibility they had one. Of course they didn't. When we got back there was a cop at my car and he threatened to tow it if I didn't move it then. So I jumped the relay with a wire ( I know dumb but I had to move it) pulled into the hospital parking lot. When o went to turn it off I noticed smoke coming from under the hood and of course I shorted the wires out where I jumped the relay.

When I got the car home I found that the chassis harness that goes from drivers side fender to pass fender and to the fuse relay box had burned a little. I also noticed the engine harness had a wire that was burned up. So I replaced both harness' but being that my car used to be an auto I couldn't figure out where to plug the trans harness ( auto harness) into the fuse relay box by the battery. So after plugging everything else in I plugged the two big gray plugs from the trans harness into two plugs from relay/ fuse box area. I'm stupid when it comes to wiring. Tried to start the car and it wouldn't start so I checked the ecu and found a short. I changed out the ecu and the car started. that's when the problems started.

First my speedo doesn't work at all. Also SOMETIMES when I take out the the key my ignition lights in my cluster stay on and won't turn off. I got it to turn off by turning the car back on a few times and it usually turns those lights off. I also noticed that as I'm driving if I go to floor it at all my car takes forever to get up to speed.

As I was driving to my friends house today to work on my car I noticed my radios power would shut off then come back on several times. Then it just shut off and wouldn't come back on. About 5 miles after that my car started to feel like it was going to die so I pulled into the closest lot and it died and wouldn't start back up. It wouldn't turn over at all and would just make a constant clicking noise. I unplugged the starter to see if it was making tha clicking noise. It ended up being the starter so I picked up one from the closest autozone and installed it. Afterwards I tried to start the car but the battery was dead so I had my friend jump it and it started BUT when I went to give it gas it wanted to die immediately. So I tried giving it has again and it died. Tried starting it but once again no battery but I heard a buzzing coming from the relay box by the battery. The EGI relay was the culprit and kept buzzing until I unplugged it. I grabbed the egi fuel relay which is the same as the EGI relay and plugged it into the EGI relay spot and that one started buzzing too so I'm guessing that part is getting constant power and won't turn off. I don't know maybe that's why my batter was drained. I'm waiting to get it towed to my house right now.

Sorry for the long explanation but I wanted to include everything. I don't think I'm forgetting anything. My car ran perfectly fine before this all happened. Please if anyone can help I would really appreciate it. Thank you!!

Looks like you got a short somewhere, after burning up wires I would take all of it out and just go over it all, you probably have some wires that are touching still, just take the whole wire harnesses and go over them, it sounds impossible or to much to do but if you want to find the problem or problems that's what I recommend

I don't think I have anything touching being that I changed bothe the chassis and engine harness. But I guess I'll just have to take it all apart to Make sure. I think the short is somewhere else in another harness and that is what blew my fuseable link in the first place which led to this whole problem.